In this paper the pore texture characteristics of the  Dalinghe reservoir of  Shahejie Formation,of Paleogene in Shuguang Oil Field were analyzed from the lithology, diagenesis, pore types and clay minerals of the reservoir, and reservoir micro-heterogeneity and its affection on development effect were studied. The textural and compositional maturation of the Dalinghe reservoir is low. The upper part of the Dalinghe reservoir consists of feldspathic litharenite and the lower part consists of lithic arkose. Intergranular pores are the major pore type , and there are also some secondary solution pores in reservoir. Pore texture is mainly large pore with medium throat , and next is medium pore with thin throat and thin pore with thin throat. Clay minerals include montmorillonite, kaolinite and illite, and  montmorillonite is the most abundant especially in lower oil formations.  To prevent damaging pore structure and oil reservoir heavily during development, different exploiting schemes should be adopted and the flowing velocity of injected fluid in oil formation should be controlled considering the heterogeneity of upper and lower formations. While injecting steam whose PH should be 9 or so, certain amount of k+ should be added .